﻿using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.IO;

/// <summary>
///ValidateCode 的摘要说明
/// </summary>
public class ValidateCode
{
    public ValidateCode()
    {
        //
        //TODO: 在此处添加构造函数逻辑
        //
    }
    public static string GetRandomCode(int CodeCount)
    {
        string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,M,N,P,Q,R,S,T,U,W,X,Y,Z";
        string[] allCharArray = allChar.Split(',');
        string RandomCode = "";
        int temp = -1;

        Random rand = new Random();
        for (int i = 0; i < CodeCount; i++)
        {
            if (temp != -1)
            {
                rand = new Random(temp * i * ((int)DateTime.Now.Ticks));
            }

            int t = rand.Next(33);

            while (temp == t)
            {
                t = rand.Next(33);
            }

            temp = t;
            RandomCode += allCharArray[t];
        }

        return RandomCode;
    }
    public static void CreateImage(string checkCode,HttpResponse Response)
    {
        int iwidth = (int)(checkCode.Length * 14);
        System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 20);
        System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(image);
        System.Drawing.Font f = new System.Drawing.Font("Arial ", 10);//, System.Drawing.FontStyle.Bold);
        System.Drawing.Brush b = new System.Drawing.SolidBrush(System.Drawing.Color.Black);
        System.Drawing.Brush r = new System.Drawing.SolidBrush(System.Drawing.Color.FromArgb(166, 8, 8));

        //g.FillRectangle(new System.Drawing.SolidBrush(Color.Blue),0,0,image.Width, image.Height);
        //			g.Clear(Color.AliceBlue);//背景色
        g.Clear(System.Drawing.ColorTranslator.FromHtml("#99C1CB"));//背景色

        char[] ch = checkCode.ToCharArray();
        for (int i = 0; i < ch.Length; i++)
        {
            if (ch[i] >= '0' && ch[i] <= '9')
            {
                //数字用红色显示
                g.DrawString(ch[i].ToString(), f, r, 3 + (i * 12), 3);
            }
            else
            {   //字母用黑色显示
                g.DrawString(ch[i].ToString(), f, b, 3 + (i * 12), 3);
            }
        }

        //for循环用来生成一些随机的水平线
        //			Pen blackPen = new Pen(Color.Black, 0);
        //			Random rand = new Random();
        //			for (int i=0;i<5;i++)
        //			{
        //				int y = rand.Next(image.Height);
        //				g.DrawLine(blackPen,0,y,image.Width,y);
        //			}

        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
        //history back 不重复 
        Response.Cache.SetNoStore();//这一句 		
        Response.ClearContent();
        Response.ContentType = "image/Jpeg";
        Response.BinaryWrite(ms.ToArray());
        g.Dispose();
        image.Dispose();
    }

}
